Abrasive wheel



April 1938- D. E. MULH-OLLAND ,2

ABRAS IVE WHEEL O riginal FiIed Jan. 22, 1955 2 Sheets-Sheet 1ATTORNEYS.

April 26, 1938. D. E. MULHOLLAND ABRAS IVE WHEEL 2 Sheets-Sheet '2Original Filed Jan 22, 1955 INVENTOR. Jawbfl/Va/%n/7nzd BY Wm,

I A TTORNEYS.

Patented Apr. 26, 1938 UNITED STATES PAT .5. NT OFFICE signor to GeneralAbrasive Company,

Inc., a

corporation of New York Application January 22, 1935, Serial No. 2,920Renewed August 7, 1937 17 Claims.

This invention relates to an abrasive article more particularly to onefor use in what is called flexible polishing, and is closely related tocopending application Serial No. 334,588, filed July 11, 1934, of whichI am one of the joint inventors.

This invention while having for its object the advantages expressed inthe afore-mentioned application, also has additional objects, one ofwhich is the provision of a sleeve which will be flexible and yet suchthat the material mounted upon it may be readily secured thereto.

Another object of the invention is the provision of a sleeve which maybe readily attached by binding on to a rigid body and which may asreadily be detached and which although of a flexible nature, may bebound at such relatively closely spaced intervals along the body as toprevent any detrimental expansion by centrifugal force.

Another object of the invention is to provide a sleeve having a flexiblefoundation upon which an abrasive is mounted which is so reinforced asto require binding to a support only at its ends and yet not undulyexpand in its middle due to centrifugal force.

Another object of the invention is to provide an abrasive article forflexible polishing, which will have a sleeve which will not be injuredby a liquid coolant and lubricant.

Another object of the invention is the forming of a sleeve by helicallywinding a strip of fabric and then securing the abrasive materialthereto, and in which the different helical layers of the sleeve, aswell as the remainder of the wheel, may be firmly and yet flexiblysecured together.

Another object of the invention is the provision of a sleeve which maybe frictioned and secured to a partially rubber abrasive bond or backingtherefor by vulcanization.

Another object of the invention is to provide a sleeve which will bedynamically balanced.

A further object of the invention is the provision of a sleeve whichwill cooperate to produce the desired efiects mentioned in theco-pending application above referred to.

With these and other objects in view, the invention consists of certainnovel features of construction, as will be more fully described, andparticularly pointed out in the appended claims.

In the accompanying drawings:

Fig. 1 is an elevation of an abrasive wheel formed in accordance with myinvention;

Fig. 2 is an elevation illustrating the helical winding of a strip offabric material which forms the inner sleeve to which the abrasivesurface and the backing therefor the same in position;

Fig. 3 is a sectional view illustrating the manner of securing thesleeve to the rigid central body by means of a wire and a means ofsecuring 5 the wire at the ends thereof;

Fig. 4 is a sectional viewof a fragmental portion of an abrasive wheelillustrating a modified construction;

Fig. 5 is a top plan view of the wheel with a 10 sheet of work beneathit and the coolant as applied thereto;

Fig. 6 is an end view of Figure 5;

Fig. 7 is a diagrammatic perspective view illus- 15 trating the actionof the liquid coolant between the abrasive wheel and work;

Fig. 8 is a plan of a fragmental portion of the sleeve of modifiedconstruction; I

Fig. 9 is a plan of the completed modified construction wheel;

Fig. 10 is a fragmental section of this modified construction of wheel.

As pointed out in the co-pending application, above referred to, thereare many difliculties ex- 25 perienced in so-called flexible polishing;and in developing a wheel to meet these conditions as set forth in theco-pending application above referred to, I have found that the use of afabric sleeve for mounting the resilient backing as well 30 as theabrasive outer surface of the wheel provides a very strong, tough anddurable manner of mounting the outer material so that parts of the wheelcan be arranged readily to be sufiiciently flexible, and the wheel maylend itself 5 readily to be bound in place by a helical wire. Thesurface of the fabric sleeve may be frictioned to which the rubberizedcomposition can. be readily secured by vulcanizing and the entireconstruction firmly secured in place and yet providing suilicientflexibility for binding the sleeve to a rigid body by means of a helicalgroove therein. This sleeve of fabric material also cooperates verynicely to accomplish the cooling and other objects mentioned in theabove re- 45 ferred to co-pending application, and affords the wheelgreat tensile strength; and the following is a more detailed descriptionof the present embodiment of this invention and illustrating thepreferred means by which these advantageous 50 results may beaccomplished:

With reference to the drawings, l0 designates a rigid body, here shownas a metallic cylinder or drum, and which may be made up in other shapesthan that illustrated. It may be mounted 66 are secured in holding thestructure shown in upon a shaft l I for rotation at the desired numberof revolutions to secure the surface speed required for the wheelmounted thereon.

Upon this metallic drum, there is removably.

mounted a unit consisting of an inner fabric sleeve, designated and anabrasive and bond therefor which may or may not be resiliently backed.This sleeve is made up from a strip l3 of fabric wound helically along asuitable arbor or core designated II. This strip of fabric is.

formed of frictioned material, that is, the Surface is'rubbed withrubber to a sumcient extent to cause the rubber toimpregnate thematerial and lodge in the interstices of the material, the frictioningtaking place on the outer surface of. the material, although it may alsotake place on the inner surface, if desired.

After the sleeve of fabric has been built up in this way, the additionallayer or layers of material is or are mounted upon the fabric sleeve. InFigures 1 to 3 I have illustrated an outer layer which is formed of anabrasive and a bond for the abrasive which is somewhat flexible andbetween this outer layer It and the sleeve there is positioned a layerIt of a material containing a larger quantity of soft rubber and whichis of acomposition to be more flexible than the outer layer It so as toabsorb some of the resiliency which may be transmitted thereto throughthe layer It. The specific materials which go to make up the layers "andI! being more fully and definitely defined in the application abovereferred to.

constituting layers spaced or in substantial contact causing it toextend the entire length of the sleeve. In either case, after theassembly is completed, vulcanizationtakes place which-firmly secures allof the ,layer It and the layer frictioned fabric J3.

-ousparts parts together; that is, layer II is secured to the I. firmlysecured 'to the After vulcanization, .the helical slot is cut in thetwo-plys II and I. to the depth of the fabric l2 and 'in the casewhere ahelicaLstrip-is laid in place, the helical cutting will follow the seamsbetween these layers, whichsometimes become vulcanized together, amLthiscutting will .clear out the part of the rubber nfaterial which has runinto the seams which is the part which is not homogeneous, and thusleave the homogenewhi'ch embrace the bonded abrasive. Thus I-.provide bythis'helical cutting of the helically laid strip a surface throughoutthe length of the wheel which is homogeneous-in that the bonded abrasiveis equally disposed throughout the mass material which is presented tothe face for abrasive action, thus providing a' more even and bettersurfaced wheel.

This helical slot may be'short or the end of the wheel as at 23, so asto prevent undue ex pansio'n from centrifugal force acting on flthethinner edge which would otherwise be formed. and in this slot startingat an opening 2| at the end 3. thereof a wire designated generally 32 isinserted through an opening 33 in thebody where it is locked by a setscrew 34 and is then wound tightly in the helical groove the entirelength of has been omitted.

the sleeve and then passed through a similar opening at the opposite endwhere it is similarly secured by another set screw 14 in the oppositeend of the drum to hold the sleeve tightly in place throughout itslength. By supporting the sleeve 5 and binding it to the drum throughoutthe length, the centrifugal force acting on the sleeve is sufficientlywell controlled so that the expansion of the sleeve by centrifugal forceis uniform and a bellying or barrel-shape effect in the middle of 10 othe sleeve when running is prevented. For removal of this abrasivesleeve, it is merely necessary to loosen the wire and take the same fromthe helical groove and then slide the sleeve from the rigid body andreplace it-with a similar sleeve 16 for further operation. J In Figure4, I have illustrated an abrasive wheel which is formed allof a singlelayer I5 of abrasive and bonded material, that is, the resilient backingsuch as It in the previously shown figure, v20

In this case, of course, the vulcanizing will secure the abrasive bondedmaterial directly to the frictioned fabric sleeve, it being of a natureto break down in use sufiiciently to expose new grain before thegrainsbecome 26 dull, and yet not so resilient as to lose the grainwithout itself wearing away. On the other hand, there is sufiicientresiliency so that flexible polishing can be had. The material used inthe sleeve is of such a 30 character as to withstand water, which is thecoolant and lubricant which I prefer to use'in the operation of thewheel, and by means of this coolant and lubricant I am able to pass thework designated 33, through a pair of wheels designated'3land 32, thecoolant being supplied to the wheel 3| by means of a conduit 33 having aplurality'bf nozzles 3|, each designed to project a fan-shaped spraytherefrom so that the coolant 3! is projected between the wheel 3| andthe 40 work in a sheet form film 33. A conduit 35 is provided fordirecting coolant to the under wheel '33 and is likewise provided with aplurality of nozzles 33 also similarly designed to project the coolantin fan-shaped manner whichjoin to I 31 is proiected with considerableforce towards 5g the contacting area of the wheel and work and moves tothe opposite side of the wheel by filling and proceeding through thegroove at the area of contact of the wheel with the work and emanates instreams such as'38, on the opposite side as of the wheelfrom thattowards which it is projected.

By-reason of the helical groove which is of a substantial depth and isfilled with water, this entire body of coolant which is in the groove somoves axially of the wheel to sweep the work one or more times eachrevolution of the wheel and more effectively cools the work than anyother known means of cooling the enga in surface area of an abradantwheel with its work, and

thus prevents .the work from becoming overheated. This overheating.sometimes permits buckling -of thin work, and where I have providedwheels acting on the surfaces of the work at the same time as thesetravel a very thin sheet of material may pass there- "through withoutbuckling or curling around'a single wheel, as sometimes occurs inpractice.

I prefer a water coolant and lubricant, althoughitwillbereadilyapparcnt-thatothsrfiuidcoolu.

in opposite direction m' ants can be utilized with effective resultswith my helically grooved wheel while the coolant is permitted andcaused to sweep the surface of the work axially of the wheel one or moretimes each revolution of the wheel.

It will be understood that I may use all character and sizes of grainsfor effecting better polishing on certain metals or alloys which aremore susceptible or better attacked by one size or character of grainthan by another.

In Figure 8 I have illustrated a modified form of fabric sleeve in thatthis sleeve is wrapped fairly closely with right and left hand turns ofwire 43 and 44 wound helically about the fabric with the same ordifierent pitches and crossing at 45 at diametrically opposite points ofthe wheel, which serves to prevent expansion of this fabric member andfirmly support the sleeve against centrifugal forces tending to expandthe sleeve into generally barrel-shape formation. These wire wrappingscompress the fabric and become indented therein, as at 46 in Figure 10,and are in turn covered with the cushion member and the abrasive andbond therefor, as shown in Figure 10, or with merely the abrasive memberwithout the cushion, as in Figure 4 and in cases of this character, thesleeve could be tightly bound by clamps 48 at its end, which would avoidthe use of the wire in the helical groove extending the length of thesleeve to secure it in position and yet would prevent the bellying orbarrelshaped effect in the center due to centrifugal force were there nosupport for the sleeve when assembled upon the steel drum.

The foregoing description is directed solely towards the constructionillustrated, but I de sire it to be understood that I reserve theprivilege of resorting to all the mechanical changes to which the deviceis susceptible, the invention being defined and limited only by theterms of the appended claims.

I claim:

1. An abrasive wheel having a rigid support, a sleeve mounted thereon, abonded abrasive portion forming its outer face and fixed to said sleeve,said bonded abrasive portion being provided with a peripheral coolantconducting groove extending inwardly to said sleeve, and means in saidgroove for securing said sleeve in position on said support.

2. An abrasive wheel having an inner sleeve, and an abrasive and bondtherefor forming its outer face and fixed to said sleeve, said sleevebeing continuous along the length of the wheel and said abrasive and bnd being provided with a coolant conducting grooveextending to saidsleeve, and means in said groove for securing said sleeve in position.

3. An abrasive wheel having a sleeve with an inner flexible layer ofmaterial and a bonded abrasive portion forming its outer face and fixedto said flexible layer, said bonded abrasive being arranged with spacedportions of face material separated by a helical groove extendinginwardly to said sleeve.

4. An abrasive wheel composed of a rigid central body adapted to bemounted on a shaft, a helically wound flexible material contacting saidbody and an abrasive and bond therefor forming its outer face and fixedto said flexible material.

5. An abrasive wheel composed of a rigid central body adapted to bemounted on av shaft, a sleeve removably mounted onsaid body and anabrasive and bond therefor forming its outer 3 face and fixed to saidsleeve, said abrasive and bond being provided with a helical grooveextending to said sleeve, and means in said groove engaging said sleeveto bind it to said body at a plurality of spaced intervals.

6. An abrasive wheel composed of a rigid central supporting body adaptedto be mounted on a shaft for rotation thereby, a sleeveremovably mountedon said body, a bonded abrasive portion forming its outerface and fixedto said sleeve, said sleeve being continuous axially of the wheel, saidbonded abrasive portion being arranged with spaced portions of facematerial separated by a helical groove extending to said sleeve, andmeans in said groove engaging said sleeve to bind it to said supportingbody at spaced intervals.

7. An abrasive Wheel composed of a rigid central body adapted to bemounted on a shaftfor rotation thereby, a fabric sleeve removablymounted on said body, a bonded abrasive portion forming its outer faceand fixed to said sleeve, and a layer of material more resilient thanthe bonded abrasive between said sleeve and said bonded abrasiveportion, said abrasive portion and backing being grooved helicallyinwardly to the depth of said fabric sleeve to provide a coolant conduitin the wheel face.

8. An abrasive wheel composed of a rigid central body adapted to bemounted on a shaft, a

fabric sleeve removably mounted on said body, a bonded abrasive portionforming its outer face and fixed to said sleeve, a layer of materialmore resilient than the bonded abrasive between said sleeve and saidbonded abrasive portion, said abrasive portion and backing being groovedhelically inwardly to said fabric sleeve, and a wire in said helicalgroove to bind the sleeve to said central body.

9. An abrasive wheel comprising an inner sleeve of fabric materialbonded granular abrasive material secured thereto, and a wire helicallywrapped about and in contact with the outer surface of said sleeve toreinforce it against expansion under the influence of centrifugal force.

and in contact with the outer surface of said 50 sleeve to reinforce itagainst expansion under the influence of centrifugal force.

11. An abrasive Wheel comprising an inner sleeve, abrasive materialsecured thereto, a wire helically wrapped about said sleeve to reinforceit against expansion under the influence of centrifugal force, saidsleeve extending beyond the abrasive at either end thereof, and bandsabout said sleeve at its ends to clamp the same in position on the bodyon which it is mounted.

12. An abrasive wheel having a rigid support, a sleeve mounted thereon,a bonded abrasive portion forming its outer face and integrally fixed tosaid sleeve, and clamping means of elongated form extending axiallyalong said sleeve and in contact with and about the outer surface of thesleeve along substantially the entire length of said clamping means forremovably securing said sleeve in position on said support.

13. An abrasive wheel having a rigid support, a sleeve mounted thereon,an abrasive portion of bonded granular abrasive material forming theouter face of said wheel, a layer of material more resilient than thebond for the abrasive material of'said outer portion and interposedbetween and integrally uniting said sleeve anid said outerbonded-abrasive 'iace portion, and clamping means about the outersurface of the sleeve and extending axially therealong for removablysecuring said sleeve in position on'said support,

said clamping means being positioned inwardly from the working surfaceof said bonded abrasive portion.

canized. to said abrasive portion to secure it in position.

ripheral abrading portion or boncbd abrasive grainssecuredtotheoutersuriaeeotthesleeve,

and clamping means about theouter suriace of the sleeve and extendingaxially therealong and circular-iv thereabout for securing said sleevein position on said support, said clamping means being positionedinwardly from the working surface of said bonded abrasive portion.

16. An abrasive wheel comprising a rigid central support, a sleevemounted thereon having a peripheral abrading portion of bonded abrasivegrains, and clamping means of elongated form extending lengthwise of thewheel and extending thereabout. and lying below the level of the workingsurface of the abrading portion for securing said sleeve in position onsaid support.

17. An abrasive wheel comprising a rigid central support, a sleevemounted thereon having a peripheral abrading portion of bonded abrasivegrains, and clamping means of helically wound Iorm engaging said sleeveand extending axially the'realong to bind it to said support at aplurality of spaced intervals extending lengthwise of the wheel andlying below the level of the working surface 01' the abrading portionfor securing said sleeve in position on said support.

DAVID E. MULHOLLAND.

